Nucleic acid detection methodologies continue to serve as a critical tool in the field of molecular diagnostics. The ability to manipulate biomolecules specifically and efficiently provides the basis for many successful detection technologies. For example, linking a chemical, biological, or physical moiety (e.g., adding a “tag”) to a biomolecule of interest is one key technology related to the subsequent manipulation, detection, and/or identification of the biomolecule.
Conventional linking technologies often rely on enzyme-assisted methods. For example, some methods to append a desired tag onto a target DNA use a ligase enzyme to join the target DNA to the tag (e.g., another DNA fragment comprising the tag, another DNA fragment to serve as the tag itself, etc.). In another method, a polymerase enzyme incorporates a tag-modified substrate of the polymerase (e.g., a dNTP or a modified-dNTP) into a nucleic acid. An advantage of these enzyme-assisted methods is that the links joining the biomolecule to the moiety are “natural” linkages that allow further manipulation of the conjugated product. However, some important drawbacks include low product yields, inefficient reactions, and low specificity due to multiple reactive groups present on a target biomolecule that the enzyme can recognize. In addition, conventional methods have high costs in both time and money.